Field of the Invention
Embodiments of the invention relate to a touch panel, a display device with the touch panel, and a method for fabricating the touch panel, and more particularly to a touch panel and a method for fabricating the same which can reduce a number of fabrication steps.
Description of the Related Art
There are various kinds of display devices which display images, such as cathode ray tubes (CRT), liquid crystal display devices (LCD), plasma display panel devices (PDP), electro luminescence display devices (ELD), and organic luminescence display devices.
The liquid crystal display device controls light transmissivity of liquid crystals by using an electric field to display a picture. For this, the liquid crystal display device is provided with a liquid crystal panel having liquid crystal cells, a backlight unit for directing a light to the liquid crystal panel, and a driving circuit unit for driving the backlight unit and the liquid crystal cells.
There has been a rapid increase of demands on a display device which is used as an input device by mounting a touch panel thereto, in which a surface of a liquid crystal panel is pressed down with a pointer (a user's finger) to input information pertinent to the pointed position. Depending on touch sensing types, in the touch panels, there are a resistance type, a capacitive type, and an infrared ray sensing type, and, recently, the capacitive type has garnered attention in view of convenience of fabrication, sensing capability, and so on.
The touch panel is provided with a sensor glass having electrodes formed thereon for sensing the touch by a capacitive system, and a cover glass arranged to face a sensor substrate. In this instance, the sensor glass is provided with a routing portion having first sensor electrodes for sensing X-axis direction capacitance, bridges each for connecting adjacent first sensor electrodes through a contact hole, second sensor electrodes for sensing Y-axis direction capacitance, connection portions each for connecting adjacent second sensor electrodes, a first routing line for supplying a signal to the first sensor electrodes and a second routing line for supplying a signal to the second sensor electrodes, and a pad portion for supplying a signal to the first and second routing lines.
A method for fabricating the touch panel requires at least five mask steps. That is, the method requires many steps including formation of metal pads and the first and second routing lines on the sensor glass with a first mask→formation of the bridges with a second mask→formation of an insulating layer and formation of a contact hole with a third mask→formation of the first and second sensor electrodes with a fourth mask→formation of an insulating layer on the first and second sensor electrodes and removing the insulating layer from a region falling under the pad region with a fifth mask, thereby increasing fabrication cost and time.